Compressor and lubricating means therefor



March 20, 1956 v w, usc ET AL 2,738,919

COMPRESSOR AND LUBRICATING MEANS THEREFOR Filed March 14, 1951 .BY M W AT TORNE Y5.

United States Patent COMPRESSOR AND LUBRICATING MEANS THEREFOR Application March 14, 1951, Serial No. 215,604

12 Claims. (Cl. 23058) This invention relates to a compressor and lubricating means therefor. The invention is particularly useful in connection with the application of motor compressor units adapted for compressing or pumping fiuids as, for example, for compressing a fluid used in refrigerating apparatus, such as Freon, methyl chloride, etc. It will be understood, however, that the invention is applicable to a variety of compressors and similar structures.

Compressors have heretofore been employed having eccentric crank pins connected with pistons and in which oil passages have been in communication with a pool of oil in the shell of the compressor unit, the oil being moved through the passages by centrifugal pumping action. Patent No. 2,146,097 dated February 7, 1939, to Touborg shows such a structure, capable of carrying the oil to a fair extent through the crank pin, but it has been difficult to carry oil effectively to higher points; This difliculty has been caused, at least in part, by the fact that particles of liquid refrigerant become entrained in the lubricating oil and as the oil moves up the passage, the surface of which is warmed by the friction of the crank pin moving within the crosshead, the entrained refrigerant vaporizes and vapor or gas so formed serves to break the continuity of flow of oil in the passage, interrupting lubrication of the moving parts.

An object of the present invention is to provide effective means for lubricating the driving shaft and the bearing surfaces of moving parts of a compressor unit or similar structure, particularly the upper portions thereof. A further object is to provide means for preventing vapor that may become entrained in the lubricant from interrupting lubricant flow. Another object is to provide means for lubricating the bearing surfaces at the forward end of the compressor piston, and also the surfaces between the valve plate and wafer valves. Yet another object is to provide an oil seal between the bearing surfaces of piston and cylinder and between the valve plate and wafer valves. A further object is to provide a lubricating means which will allow an oil level to be maintained below the compressor mechanism, per se, thereby minimizing noise transfer from said mechanism to the outer housing. A still further object is to provide means for returning oil overflowing from an upper portionof the shaft and utilizing the same while returning it to the oil pool in the bottom of the compressor unit shell. Other specific objects and advantages will appear as the specification proceeds.

The invention is shown in an illustrative embodiment by the accompanying drawing, in which- Figure 1 is a vertical sectional view of a compressor unit equipped with oil-feeding means embodying our invention; Fig. 2, a broken side view in elevation of the vertical shaft and'crank pin; Fig. 3, a sectional detail View, the section being taken as indicated at line 33 of Fig. 2.

Within the shell is mounted a chassis or frame'12 which may be supported bya plurality of springs 13 or other means so that the'lower portion of the chassis or frame is above the pool of oil. Within the frame 12 is mounted a vertical shaft 14 equipped with a weight member 15 and with an eccentric orcrank pin 16. The crank pin 16 is mounted within a slide member or cylindrical cross-head 17 and the cross-head 17 is slidably mounted within the cylindrical yoke 18. Theyoke 18 is sealed or otherwise secured to a piston 19 slidably mounted within a cylinder 20. The piston chamber is controlled by a wafer valve 21 of well-known construction and the frame provides the usual inlet and outlet passages communicating with the piston chamber. Since the frame and compressor unit structure is well-known in the art, it is believed that a detailed description herein is unnecessary. No claim herein is made to the compressor structure per se. The general organization and operation of the compressor unit is set out in detail in Touborg Patent No. 2,146,097 which issued February 7, 1939.

Suitable means for rotating the shaft 14 may be provided. In the illustration given, a rotor 22 is secured to the upper end of the shaft 14 and the rotor is provided with cooling vanes 23. A stator 24 is carried by the casing around the rotor 22.

The crank pin 16 is provided with an upwardly extending passage 25, the passage terminating at 26 in an outlet opening in the surface of shaft 14. The bottom of passageway 25 is nearer the vertical axis of shaft 14 than is the upper portion, the passageway thus being inclined from the vertical. A tube 27 is inserted into the lower end of the passage 25, the tube being bent in such a way that its inlet 28 is substantially in vertical alignment with the vertical axis of shaft 14. If desired, the crank pin 16 itself may be extended downwardly into the pool 11 and the passage 25 may be inclined to bring the inlet thereof substantially in alignment with the vertical axis of shaft 14. We prefer, however, to terminate the crank pin above the pool of oil and to provide the tube 27 which forms an extension of passage 25, inasmuch as turbulence is thereby reduced resulting in more positive pumping, and also the tube can be bent to place the inlet of the vertically inclined passage on the vertical axis of-shaft 14 under conditions in which the distance between the axis of the crank pin 16 and shaft 14 has been increased to increase the stroke of the piston. The crank pin 16 is provided with a short horizontal passage 29 connecting the inclined passage 25 and the surface of the crank pin. From the outlet opening 26 of the inclined passage 25 there extends upwardly along the shaft 14 a spiral groove 30, as shown in Figures 1 and 2 for'leading oil upwardly about the shaft.

In addition to the inclined passage 25 described above, and hereinafter referred to in these specifications as the lower inclined passage, we provide the shaft and its crank pin with an inclined passage 31, hereinafter referred to as the upper inclined passage. upper inclined passage 31 is located on the surface of crank pin 16 at a point opposite and slightly above the outlet of the horizontal passage 29 and is connected therewith by spiral groove 29a. The upper inclined passage 31 is at such an angle to the vertical that it merges at its upper end with the upper end of the lower inclined passage 25. A portion of the surface area of the crank pin 16 is flattened at 33. a v v The inner frame portion 12a about shaft 14 is preferably provided near its top with an overflow passage 34 permitting oil to be fed from the top of passage 30 through overflow passage 34 and into a receptacle 35 provided by the frame 12. The oil within receptacle 35 flows downwardly through passage 36. Plug 41contains an orifice 42, said orifice being of predetermined size, that connects withthe suction chamber of the compressor and a portion of the downwardly flowing oil is drawn through this orifice. downward flow follows the path shown in Figure 1, flow- Lower end 32 of the The balance of the oil in its ing over and lubricating the walls of the piston 19 after which the oil flows to the bottom of the shell 10.

The cylinder may be equipped with a bracket 39 for supporting a screen or filter 40 which extends about the inlet 28 of tube 27.

Operation In the operation of the compressor apparatus, and more particularly the lubricating means thereof, shaft 14 is rotated by the operation of rotor 22 and stator 24 and the eccentric 16 is rotated. In this operation, while the eccentric moves in a circular course, sliding the crosshead 17 back and forth and moving the yoke 18 and piston 19 back and forth, the intake portion of tube 27 remains very much in line with the longitudinal axis of shaft 14. Since the lower inclined passage is inclined away from the axis of shaft 14, centrifugal action causes oil to fiow from the intake 28 upwardly into passage 25. Because of the difference in density of the oil and slugs of vapor entrained therein the centrifugal action throws the oil through the horizontal passage 29. Vapor continues to rise along the lower inclined passage 25 to its point of junction with upper inclined passage 31. The oil thrown out through the passage 29 moves upwardly along the groove 29a to the flat 33 and the lower end 32 of the upper inclined passage 31. The flat serves as a metering device to pass a portion of the oil upwardly along the surface of the crank pin 16 and thence downwardly to lubricate the surface between the crosshead 717 and the cylindrical yoke 18. The greater portion of the oil is carried by centrifugal force upwardly along the upper inclined passage 31, the oil as it reaches the junction of passage 31 with lower inclined passage 25 carrying with and ahead of it refrigerant vapor rising up passage 25, the oil and vapor moving out the outlet opening 26 and thence upwardly along the spiral groove 30. hits upward movement the oil lubricates shaft 14. Upon reaching the top of groove the oil flows downwardly through overflow passage 34, thereby lubricating the thrust bearing surfaces, and into receptacle 35 in the frame thence through passage 36 past the plug 41 in which there is an orifice 42. The pressure differential between the side of the orifice exposed to the suction chamber 43 and the opposite side of said orifice, combined with the aspirator effect of the gaseous refrigerant passing the surface of the orifice plate exposed to the suction chamber, draws a metered quantity of the downwardly flowing oil through the orifice 42 and into the suction. chamber 43 where it is picked up by the refrigerant to lubricate the surfaces of the suction and discharge valves and the forward bearing surfaces of the piston 19 and cylinder 20. The balance of the downwardly flowing oil passes across and lubricates the surface of the reciprocating piston 19 and then flows into the pool of oil at the bottom of the compressor shell.

While the oil mechanism has been described specifically in connection with a compressor unit, it will be understood that the invention is applicable to other rotating devices in which it is desired to draw oil from a pool upwardly through rotating parts whose surfaces are to be lubricated. The lubricating area shown is, however, particularly useful in connection with a compressor of the construction shown.

While in the foregoing specification we have shown a specific lubricating device in considerable detail for the purpose of illustrating an embodiment of the invention, it will be understood that such details of structure may be varied widely by those skilled in the art without departing from the spirit of our invention.

We claim:

1. In a structure of the character set forth, a shell providing a chamber adapted to support a pool of oil in the lower portion thereof, an inner frame suPpOrted within said shell, :1 motor carried by said frame, a vertical shaft rotatably mounted in said frame and driven by' said motor, said shaft being provided at its lower end with an eccentric crank pin, a cylinder provided by said frame, a piston in said cylinder, and a driving connection between said crank pin and said piston, said crank pin having an upwardly extending oil passage therein terminating at one side of the shaft and at a spaced distance laterally of the vertical axis of the shaft and having an inlet in an oil pool at a point generally in alignment with the vertical axis of the shaft, said crank pin having an inclined oil passage merging with the upper portion of said upwarc ly extending passage and having an inlet above the inlet of said upwardly extending passage and in generally vertical alignment with the vertical axis of said shaft, said crank pin also having a passage extending laterally from said upwardly extending passage, and means for providing a flow of oil from the laterally extending passage to the inlet of said inclined passage.

2. In a compressor unit, a shell providing a chamber adapted to support a pool of oil in the lower portion thereof, an inner frame supported within said shell, a motor carried by said frame, a vertical shaft rotatably mounted in said frame and driven by said motor, said shaft being provided at its lower end with an eccentric crank pin, said frame providing a cylinder, a piston in said cylinder, a driving connection between said crank pin and said piston comprising a hollow cylindrical yoke and a cylindrical cross-head therein apertured to receive said crank pin, said crank pin having an upwardly extending oil passage therein terminating at one side of the shaft and at a spaced distance laterally of the vertical axis of the shaft and having an inlet in an oil pool at a point generally in alignment with the vertical axis of the shaft, said crank pin having an inclined oil passage merging with the upper portion of said upwardly extending passage and an inlet therebelow and above the inlet of said upwardly extending passage, said inlet of the said inclined passage being in generally vertical alignment with the vertical axis of said shaft, said crank pin also having a passage extending laterally from said upwardly extending passage, and means for providing a flow of oil from the laterally extending passage to the inlet of said inclined passage.

3. In a compressor unit, a shell providing a chamber adapted to support a pool of oil in the lower portion thereof, an inner frame supported within said shell, a motor carried by said frame, a vertical shaft rotatably mounted in said frame and driven by said motor, said shaft being provided at its lower end with an eccentric crank pin, said frame providing a cylinder, a. piston in said cylinder, a driving connection between said crank pin and said piston comprising a hollow cylindrical yoke and a cylindrical cross-head therein apertured to receive said crank pin, said crank pin having an upwardly extending oil passage therein terminating at one side of the shaft and at a spaced distance laterally of the vertical axis of the shaft and having an inlet in an oil pool at a point generally in alignment with the vertical axis of the shaft, said crank pin having an inclined oil passage merging with the upper portion of said upwardly extending passage and an inlet therebelow and above the inlet of said upwardly extending passage, said inlet of the said inclined passage being in generally vertical alignment with the vertical axis of said shaft, and said crank pin being provided with a laterally-extending passage communicating with said upwardly extending passage and with a peripheral passage extending between said laterallyextending passage and the inlet of said inclined passage.

4. In a compressor unit, a shell providing a chamber adapted to support a pool of oil in the lower portion thereof, an inner frame supported within said shell, a motor carried by said frame, a vertical shaft rotatably mounted in said frame and driven by said motor, said shaft being provided at its lower end with an eccentric crank pin, said frame providing a cylinder, a piston in said cylinder, a driving connection between said crank mam pin and said piston comprising ahollow' cylindrical yoke and a cylindrical cross-head therein apertured to receive said crank pin, said crank pin having an upwardly extending oil passage therein terminating at one side of the shaft and at a spaced distance laterally of the vertical axis of the shaft and having an inlet in an oil pool at a point generally in alignment with the vertical axis of the shaft, said crank pin having an inclined oil passage merging with the upper portion of said upwardly extending passage and an inlet therebelow and above the inlet of said upwardly extending passage, said inlet of the said inclined passage being in generally vertical alignment with the vertical axis of said shaft, and said crank pin being provided with a laterally-extending passage communicating with said upwardly extending passage and with a peripheral passage extending between said laterallyextending passage and the inlet of said inclined passage, said crank pin being flattened about said inlet of said inclined passage.

5. In a motor-operated device equipped with means for providing an oil pool, a vertical shaft supported for rotation by said motor, said shaft being provided at its lower end with an eccentric crank pin, a cross-head apertured to receive said crank pin, a cylindrical yoke slotted to receive said crank pin and slidably receiving said crosshead, a piston fixed to said yoke, and a cylinder receiving said piston, said crank pin having an upwardly extending inclined passage extending therethrough and equipped at its bottom with a tube having an inlet within said oil pool at a point generally in alignment with the vertical axis of said shaft, said upwardly extending passage terminating in an outlet at the side of said shaft laterally of the vertical axis thereof, said shaft having an oil passage about the periphery thereof communicating with said outlet, said crank pin having a laterally-extendingpassage communicating with said upwardly extending passage and a peripheral passage communicating with said laterallyextending passage and extending upwardly along the peripheryof said crank pin, said crank pin having also a second inclined passage merging with the upwardly extending passage near the upper end thereof and having a lower inlet at the side of the crank pin communicating with said peripheral passage.

6. In a motor-operated device equipped with means for providing an oil pool, a vertical shaft supported for rotation by said motor, said shaft being provided at its lower end with an eccentric crank pin, a cross-head apertured to receive said crank pin, a cylindrical yoke slotted to receive said crank pin and slidably receiving said crosshead, a piston fixed to said yoke, and a cylinder receiving said piston, said crank pin having an upwardly extending inclined passage extending therethrough and equipped at its bottom with a tube having an inlet within said oil pool at a point generally in alignment with the vertical axis of said shaft, said upwardly extending passage terminating in an outlet at the side of said shaft laterally of the vertical axis thereof, said shaft having an oil passage about the periphery thereof communicating with said outlet, said crank pin having a laterally-extending passage communicating with said upwardly extending passage and a peripheral passage communicating with said laterally-extending passage and extending upwardly along the periphery of said crank pin, said crank pin having also a second inclined passage merging with the upwardly extending passage near the upper end thereof and having a lower inlet at the side of the crank pin communicating with said peripheral passage, said crank pin being flattened about the inlet of said inclined passage.

7. In a compressor unit, a shell providinga chamber adapted to support a pool of oil in the lower portion thereof and a pool of oil in the upper portion thereof, an inner frame supported within said shell, a motor carried by said frame, a vertical shaft rotatably-mounted in said frame and driven by said motor, said shaft being provided at its lower end with an eccentric crank pin, said frameproviding a cylinder and a suction chamber com municating therewith, a piston in said cylinder, a driving connection between said crank pin and said piston comprising a hollow cylindrical yoke and a cylindrical crosshead therein apertured to receive said crank pin, said crank pin having an upwardly extending oil passage therein terminating at one side of the shaft and at a spaced distance laterally of the vertical axis of the shaft and having an inlet in said lower oil pool at a point generally in alignment with the vertical axis of the shaft, said crank pin having an inclined oil passage merging with the upper portion of said upwardly extending passage and having an inlet therebelow and above the inlet of said upwardly extending passage, said inlet of the ,said inclined passage being in generally vertical alignment with the vertical axis of said shaft, said shaft being provided with an upper passage communicating with said upwardly extending oil passage and leading to a point where oil flows therefrom into said upper oil pool, said frame providing a passage leading from said upper pool downwardly and adjacent said suction chamber, a passage establishing communication between said last-mentioned passage and said suction chamber, and an apertured plug therein providing an orifice through which lubricant flowing from said upper pool is drawn into said suction chamber.

8. In a motor-operated device equipped with means for providing an oil pool, a vertical shaft supported for rotation by said motor, said shaft being provided at its lower end with an eccentric crank pin, compressor means actuated by said crank pin by a driving connection mounted thereon, said crank pin having an upwardly extending inclined passage therein, said passage having an intake communicating with an oil pool and an outlet on the surface of said shaft and spaced outwardly from said intake so that centrifugal action causes fluid to flow upwardly in said passage when said shaft and crank pin are rotated, said crank pin having a laterally and outwardly extending passage communicating with said upwardly extending passage at a point intermediate the intake and outlet thereof, said crank pin also having an inclined passage therein, said inclined passage having an inlet above the intake of said upwardly extending passage and an outlet in the surface of said shaft and spaced outwardly from said inlet so that centrifugal action causes oil to flow upwardly in the inclined passage when said shaft and crank pin are rotated, and means for providing a flow of oil from the laterally extending passage to the inlet of said inclined passage.

9. The structure of claim 8 in which the upper end of said inclined passage merges with the upwardly extending passage at a point above said laterally extending passage.

10. The structure of claim 9 in which said laterally extending passage terminates in an outlet on the surface of said crank pin and the inlet of said inclined passage is on the surface of said crank pin, and said crank pin is provided with a peripheral passage extending between said laterally extending passage and the inlet of said inclined passage.

11. In apparatus of the character described, a casing providing a reservoir therein adapted to receive a mixture of two fluids, at least one of the fluids being in the liquid state and having a greater density than the other of the fluids, a generally vertical shaft supported in said casing for rotation and being equipped at its lower end with an eccentric crank pin, said crank pin having a first upwardlyinclined passage therein provided at its lower end with an inlet spaced inwardly from the peripheral surface of the pin and with an outlet above said inlet and spaced outwardly therefrom, said crank pin having also a laterally-extending passage in open communication with said upwardly-extending passage intermediate the inlet and outlet thereof and having an outlet on the peripheral surface of said pin, said pin having also a second upwardlyextending inclined passage provided with an inlet above the outlet of said laterally-extending passage and at the peripheral surface of said pin and merging with said first upwardly-extending passage adjacent the upper end thereof, means about the peripheral surface of said crank pin providing for the flow of liquid from the outlet of said laterally-extending passage to the inlet of said second inclined passage, means for establishing flow communication between the inlet of said first upwardly-extending passage and a fluid pool in said reservoir, and means for rotating said shaft.

12. In a compressor unit, a shell providing a chamber adapted to receive a pool of oil in the lower portion thereof, an inner frame supported Within said shell, a vertical shaft rotatably mounted within said frame, stator and rotor means for rotating said shaft, said shaft being provided at its bottom with an eccentric crank pin, said crank pin having a passage extending upwardly therethrough, a tube communicating with the lower end of said passage and having an inlet generally in alignment with the vertical axis of said shaft, a screen vessel supported by said frame about the inlet of said tube, said frame providing a cylinder, a piston in said cylinder, and driving connections betweensaid crank pin and said piston including a hollow cylindrical yoke fixed to said piston and slotted and being inclined downwardly and laterally to form an,

inlet generally in alignment with the vertical axis of said shaft, and means for providing a flow of oil from the lowermost of saidoutlet passages to the inlet of said inclined passage. 7

References Cited in the file of this patent UNITED STATES PATENTS Smith June 23, 1942 Hume Apr. 18, 1950 

